Toy speed boats



l l l I I l I Oct-28,1958 ,B L. HlRscl-l ETAL 2,857,703 I TOY SPEED BOATS Fi-led Dec. 26, 1956 2 Sheets-Sheet l H g E- INVENTORS BENJAMIN L. H/RSCH BY HENRY H/RSCH Oct. 28, 1958- B. HIRSCH ETALQ 2,857,708 TOY SPEED BOATS Filed Dec. 26, 1956' 2' sheets-sheet 2 *jigum' INVENTORS BENJAM/N L. H/RSCH HENRY H/RSGH ATTORNEYS United States Patent TOY SPEED BOATS Benjamin L. Hirsch and Henry Hirsch, Toledo, Ohio, assignors to Kellogg Company, Battle Creek, Mich, a corporation of Delaware Application December 26, 1956, Serial No. 630,624

5 Claims. (Cl. 46-93) This invention relates to toy boats of the type that are propelled by the action of agents such as camphor or certain soaps or detergents which when they touch the surface of water weaken the cohesion forces among the molecules of water. A typical toy boat of this type, as heretofore known, consists of a flat splinter of wood trimmed to the approximate shape of a boat having a pointed prow and a blunt stern. A notch is cut into the stern and a small piece of gum camphor is squeezed into the notch. If such a toy boat is placed in a clean vessel of clear tap water it will glide along the surface of the water for a limited time until the small piece of gum camphor is exhausted or until the forces of molecular cohesion at the surface of an area of water surrounding the toy have been weakened to equilibrium. The propulsive efiect resulting from thus unbalancing the forces of mole cular cohesion at the surface of water, usually called surface tension, have heretofore been sufiicient topropel only toys which were small in size and light in weight, e. g. of the order of one gram.

One of the objects accomplished by the instant invention is the utilization of so-called surface tension to propel toy boats having dimensions and weights greatly exceeding dimensions and weights that have heretofore been practicable for toy boats of this type.

Another object is the provision of means to propel a toy boat of this type in a manner to greatly increase the ratioof propulsive effect to the rate of concentration of the agent as a solute in the surface of the water through which the boat is being propelled.

Another object is to provide means for so applying the agent to the surface of the water as to greatly increase the ratio of the propulsive effect to the rate of consumption of the agent.

Surface tension causes the surface of the water in which a toy boat is floating to act somewhat like a stretched contractable mebrane. When the surface tension is broken or weakened at any point the surface surrounding the weakened point pulls away in all directions. If the weakened point is at the stern of a boat the surface tension moves the boat forwardly, and if the surface tension is weakened continuously at the stern of the boat, the boat continues to move forwardly.

Heretofore the only known practicable way in which the efficiency of the propulsive effect could be improved was by making the boat smaller and lighter. Indeed acceptable performance required the boat to be so small and light that its interest as a toy replica of an actual speed boat was almost lost. Moreover the tiny toy boats as heretofore constructed were fiat bottomed surface skimmers without appreciable draft to retard their movements. They were incapable of responding to rudders or even of dragging rudders through water below the surface with sufficient speed to control their courses.

Camphor or other agent fed to a point in the surface of the water causes the surface to pull away in all directions, rearwardly, to the left and to the right as well as ahead. Only the forward component of the pull is utilized to propel the boat. The camphor or other agent that goes into solution below the surface is worse than Wasted since it contaminates the water and relaxes the surface tension which is the source of the force that is utilized to propel the boat. For these reasons efficiency of performance cannot be much improved by increasing the size of the piece of camphor that is in contact with the water.

We have discovered however that weakening the surface tension at a plurality of points spaced apart transversely of the direction in which the boat is being propelled not only can increase the propulsive force but can increase the force disproportionately to the rate of saturation of the water and disproportionately to the rate of consumption of the agent.

We have discovered also that if the tension weakening agent is stationed upon the top of and adjacent the edge of a fin or ledge which is not submerged but the bottom of which is in contact with the water the surface of the water will rise upwardly over the edge of the fin with a concave meniscus and contact the tension weakening agent. When thus contacted the agent is dissolved only at the surface and is not worse than wasted by going into solution beneath the surface where it has the deleterious effect of contaminating the water.

This specification and the accompanying drawings describe and illustrate a preferred embodiment of the invention but are not intended to impose limitations upon its scope.

In the accompanying drawings:

Fig. I is a plah view of a toy speed boat embodying the invention;

Fig. II is a side elevational view thereof;

Fig. III is a rear elevational view thereof;

Fig. IV is a diagram on an enlarged scale showing components of movement of the surface of water the surface tension of which is being weakened at a plurality of points; and

Figs. V, VI and VII are schematic sketches showing modified forms of the invention.

The toy boat has a hull 1 with a pointed prow 2 and a blunt stern 3. The deck 4 of the hull has a cockpit opening 5 containing a seat 6. A splash shield 7 extends along the front of the cockpit opening and a steering wheel 8 is located above and behind the splash shield. A simulated hatch cover 9 extends over the deck 4 from the cockpit opening 5 toward the stern 3.

Projecting from the after parts of the sides of the hull 1 and from the stem 3 is a fin 10. When the toy boat is floating motionless in water the fin 10 lies in a plane that slopes downwardly and rearwardly with the rear edge of the fin at the surface of the water. In the form shown in the drawings the width of the fin 10 is greater than the width of the hull 1 amidships.

Located above rear edge of the fin 10 are stations 11, 12 and 13, in the form of small abutments one at each rear corner of the fin 10 and one at the center of the fins rear edge, against which a propelling agent can be applied. The displacement and the trim of the boat are such that the rear edge of the fin 10 touches the surface of the water but is not submerged. Forces of adhesion (i. e. such forces as cause water to rise in capillary tubes) cause the surface of the water to rise over the edge of the fin 10 so that the agent will come into contact with the surface of the water that extends in a thin film over the rear edge of the fin 10. The propellant stations are so placed that the bits of propellant barely touch the surface of the water. Moreover extension of the fin 10 under the propellant prevents it from being wasted by being dissolved downwardly. The propellant stations are spaced apart far enough so that the cohesive forces among the water molecules are weakened at points which are definitely separated from each other.

While it is not a requisite of a patent specification that it expound any theory of operation of the invention and while it is not necessary that any theory of operation even be known to the applicants, the diagram of Fig. IV and the following explanation are presented as probable reasons for the rather incredible fact that the inventors arrangement of the propulsive stations 11, 12 and 13 results in a propulsive eifect that is more than three times the propulsive effect that any one of those stations would have it is were acting alone. When the surface of water is set in motion by weakening the molecular cohesion at any point such as point 12, the surface moves away in all directions as a ripple moves away in all directions from a point where a stone has been dropped into a pond. Upon close observation the expanding ripple-like pattern of surface movement is faintly visible. The direction of movement away from the point of disturbance is radial as indicated by the arrows in Fig. IV unless and until it is obstructed or deflected. Where movement from one center of disturbance (i. e. station 12) encounters movement from another center of disturbance (i. e. station 13), it is deflected as indicated by the broken arrows of Fig. IV. Thus, nearly all the movement that is so deflected is converted into movement that carries the boat forwardly. The sum of these deflected movements is much greater than the sum of the forward components of undeflected radial movements emanating from an equivalent set of sources not spaced apart transversely of the direction in which the boat is being propelled.

The surface movement resulting from the release of tension at a station extends over the entire area of the water, the amount of movement at any particular place in the area being proportional to the distance of that particular place from the spot where the agent goes into solution. The movement continues only while the agent is going into solution. When the supply of water in contact with the undissolved agent is exhausted the surface movement ceases. at the point of contact must be constantly replenished.

According to this invention the spacing between the stations 11, 12 and 13 plays a major role in replenishment of the supply of fresh water to the stations. The surface water in the space between two stations does not acquire momentum in a direction away from either station and toward the other. Hence uncontaminated water from the space between the stations readily replaces the contaminated water at the stations. As the boat goes forward, strips of clean water alternate with streaks of solution in the boats wake, thus enhancing the realistic effect of multiple propulsion.

This invention makes practicable the utilization of the properties of surface tension to propel toy boats more than ten times heavier than could be effectively propelled by converting static surface tension into dynamic surface movement prior to this invention. A boat such as illustrated in Figs. I, II and III, the operation of which is eminently satisfactory, has been constructed with the following dimensions and weight:

Length inches 4 Width across beam do 1% Width of stem do Width of fin do 1% Gross weight grams 12 Hence the supply of fresh water' requirement being that the stations be spaced apart transversely of the direction of movement of the boat rather than bunched together.

Camphor and menthol and some detergents are examples of propellants that can be used with the above described boat. The propellant preferably is a paste at ordinary temperatures so that it can be conveniently applied to the propellant stations. Either camphor or menthol can be made into a paste by adding a small proportion of ethyl alcohol. Or they can be blended in the ratio of nine grams of camphor to one gram of menthol. In such case the blend is a paste even though no solvent is added.

The invention is susceptible of further variation within the spirit and scope of the subjoined claims.

We claim:

1. A toy boat comprising, in combination, a boatshaped hull, a fin extending from the sides and rear of said hull and sloping downwardly and rearwardly and having a transversely extending rear edge, the displacement and trim of said toy boat when floating in water being such that the rear edge of said fin normally touches the surface of the water without being submerged, and a plurality of stations for charges of a surface tension weakening agent, each station including a protuberance projecting upwardly from said fin, said stations being lo cated upon said fin and spaced from its rear edge, whereby forces of adhesion between the rear edge of said fin and the water cause the surface of the water to rise over the edge of said fin into contact at said stations with such surface tension weakening agent, said stations being spaced apart transversely sufiiciently to separate the points of contact by substantial gaps of fresh water.

2. A toy boat comprising, in combination, a boatshaped hull, a fin extending from the sides and rear of said hull and sloping downwardly and rearwardly and having a transversely extending rear edge, the displacement and trim of said toy boat when floating in water being such that the rear edge of said fin normally touches the surface of the water without being submerged, and a plurality of stations for charges of a surface tension weakening agent, said stations being located upon said fin and spaced from its rear edge, whereby forces of adhesion between the rear edge of said fin and the water cause the surface of the water to rise over the edge of said fin into contact at said stations with such surface tension weakening agent, said stations being spaced apart transversely sufficiently to separate the points of contact by substantial gaps of fresh water.

3. A toy boat comprising, in combination, a boatshaped hull, a fin extending from the rear of said hull and having a transversely extending rear edge, the displacement and trim of said toy boat when floating in water being such that the rear edge of said fin normally touches the surface of the water without being submerged, and a plurality of stations for charges of a surface tension weakening agent, each station including a protuberance projecting upwardly from said fin, said stations being located upon said fin and spaced from its rear edge, whereby forces of adhesion between the rear edge of said fin and the water cause the surface of the water to rise over the edge of said fin into contact at said stations with such surface tension weakening agent, said stations being spaced apart transversely sufficiently to separate the points of contact by substantial gaps of fresh Water.

4. A toy boat comprising, in combination, a boatshaped hull, a fin extending from the rear of said hull and having a transversely extending rear edge, the displacement and trim of said toy boat when floating in water being such that the rear edge of said fin normally touches the surface of the water without being submerged, and a station for a charge of a surface tension weakening agent, said station including a protuberance projecting upwardly from said fin, said station being located upon said fin and spaced from its rear edge, whereby forces of adhesion between the rear edge of said fin and the water cause the surface of the water to rise over the edge of said fin into contact at said station with such surface tension weakening agent.

5. A toy boat comprising, in combination, a boatshaped hull, a fin extending from the rear of said hull and having a transversely extending rear edge, the displacement and trim of said toy boat when floating in water being such that the rear edge of said fin normally touches the surface of the water without being submerged, and a station for a charge of a surface tension weakening agent, said station being located upon said fin and spaced from its rear edge, whereby forces of adhesion between the rear edge of said fin and the water cause the 15 surface of the water to rise over the edge of said fin into contact at said station with such surface tension weakening agent.

' References Cited in the file of this patent UNITED STATES PATENTS 2,439,649 Cohn Apr. 13, 1948 2,607,160 Forrest Aug. 19, 1952 Tomak et a1 Mar. 19, 1957 FOREIGN PATENTS 

